Rotary pump



M y 1943- R. E. B. WAKEFIELD ,318,346

ROTARY PUMP Filed March 1, 1941 B A2 9 6 A2 B2 l 7 7 1 A I; d 5

-r-c E A n Ev L d A I INVENTOR RICHARD E B. WAKEFIELD ATTORNEY therefrom toward said arch.

Patented May 4, 1943 UNITED STATES PATENT OFFICE ROTARY PUMP Richard E. B. Wakefield, Aidan, Pa., assignor to The Selas Company, Philadelphia, Pa., a 001-- poration 01 Pennsylvania Application March 1, 1941, Serial No. 381,353

3 Claims. (01. ins-"137) in heating the cabin or other enclosed space of an airplane.

My improved pump is of the rotary impeller, sliding piston blade type, and is characterized in particular by the form and character of the piston blades and the means employed to permit and accommodate .their radial movements required to maintain their contact with the peripheral wall of the pump chamber in which the impeller rotates.

The various features of novelty which charac-' terize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages, and specific objects attained with its use, reference, should be had to the accompanying drawing and descriptive matterin which I have illustrated and described a preferred embodiment of the invention.

Of the drawing: I 1

Fig. 1 is a section through the pump housing and impeller, taken transversely to the impeller axis;

Fig. 2 is a section taken similarly to Fig. 1, but with the impeller in a different angular position relative to the housing,. from that shown in Fig. 1; and

Fig. 3 is a section through the impeller taken on the line 33 of Fig. 1.

My improved pump in its preferred form shown in the drawing comprises a pump housing or body A formed with a pump chamber B of cylindrical form, and closed at one end by a removable head A, and formed with inlet and outlet passages B and 13 opening to. the pump chamber through its peripheral wall and separated from one another by a peripheral wall section or are A which may well be, and as shown is, in the neighborhood of 45. A rotary pump impeller C is mounted in the pump housing to rotate about an axis parallel to the axis of the pump chamber, but laterally displaced The impeller extending as shown through chamber B, and comprises comprises a shaft C" the end wall of the chamber, and is formed with a diametral slot,

orkerf C which extends throughout its length between the planes of the end surfaces of the pump impeller body. Mounted in the opposite end portions of the slot C are piston blades D and D each formed oflaminae d. In the preferred form of the inventionthe laminae d are all alike and are formed of a self-lubricating metal, such as a lead, tin and antimony alloy.

As shown, each of the piston blade'sis composed of live laminae, eachparallel to the side walls of the-slot C? and of a width equal to the axial depth of the pump chamber B, and of a length somewhat shorter than the radius of the pump chamber.

Mounted in the slot C between the adjacent ends of the piston blades D and DA is a body E of a rubber-like material, which, because of its mechanical strength and immunity to attack by gasoline, may well be the synthetic rubber commercially known as neoprene. The body E may advantageously be .so'initially shaped and proportioned that with the maximum separation-of the piston blades D and D, which occurs when the slot C is transverse to. the chord of the are A as shown in Fig. 1, the body will be sufllciently compressed to provide an effective seal against longitudinal leakage flow through the slot, and so as not to require undue compression to accommodate the movements of approach of the blade laminae a as-the impeller.

turns into its position shown'in Fig. 2 in which the minimum separation of the blades occurs. In operation with the impeller rotating in the direction of the arrow, as shown in Fig. 1, as 4 either piston blade, D or DA, moves away from the inlet port B, gasoline will pass through the inlet B into theportion of the pump chamber which is. back of said piston blade and is between the peripheral walls of the pump cham-, her and impeller body, and until the other blade, D or D, respectively, moves into position in which it extends between the inlet and said portion of the pump chamber. When thereafter the movement of the first mentioned blade brings the portion of the pump chamber back of it into communication with the outlet port B, the gasoline in "said pump chamber will be expelled through said port as the latter-is apthe pump chamber and impeller, each piston blade lamina is moved in the direction of its length into the impeller by the peripheral wall of the pump chamber during a portion of each rotation of the impeller and isgiven a return movement during the remainder of the impeller rotation by the spring action of the compressed body E and as a result of centrifugal force, action. The different laminae d reach their positions of maximum and minimum expansion from the corresponding end of the slot C in -diil'erent angular positions of the impeller, and

in consequence the .difierent laminae of the group, or bundle forming a single piston blade D or D, are constantly moving in the direction of their lengths relative to one another. This movement is accommodated by the neoprene body E which is compressed, and expands as required to keep the space in the slot C between the adjacent ends of the two piston blades filled and sealed against longitudinal leakage flow through the slot. By forming the laminae of a self-lubricating alloy, the laminae wear is kept desirably small, and wear of the pump chamber walls may be kept insignificantly small during the operative life of the pump which as now contemplated will be of the order of three hund'red flying hours or so. The pump impeller and body' may be made of any suitable materials which for the airplane service contemplates may well be a strong light weight alloy such.

as duralumin.

For the particular airplane heating system use way of limitation. For its intended flying life oi. three hundred flying hours or so my pump may well require no repairs or replacements, however,

if pump leakage develops as a result of wear or deformation of the laminae d or of impairment of the rubber-like body E, those parts .can' be readily, quickly and easily replaced and without requiring the use of tools or implements not included in the usual kit of an airplane mechanic.

While in accordance with the provisions the statutes I have-illustrated and described the best' form of embodiment 01 my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosedwithout departing from the spirit of my invention as set forth in the appended claims and that in somev cases certain features of my invention may be used to advantage without a correspondi use of other features.- l

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A small, high speed pump of the rotary impeller type comprising a housing formed with a cylindrical pump chamber and with an inlet to. and an outlet from said chamber and an impeller comprising a cylindrical body smaller in diameter than said chamber and mounted to rotate in said chamber about an axis laterally displaced from the pump chamber axis so that said body is in contact with the peripheral wall otthe pump chamber at one side of the axis of the latter, said impeller body being formed with a diametral slot, piston blades mounted in the opposite end portions oi said slot and each in the form of a bundle of laminae extending longitudinally of the slot with their side surfaces parallel to the-impeller axis and each longitudinally movable independently oi the others and a body of rubberlike material interposed within said slot between the adjacent ends of the laminae forming said piston blades and compressed by the latter.

2. In a pump of the type comprising a cylindrical pump chamber, a cylindrical impeller body smaller in diameter than said pump chamber and mounted to rotate in said chamber about an axis so displaced from the pump chamber axis that the peripheral walls of the body and chamber are in contact at one side of the pump chamber axis, said impeller body having a slot extending into it from its peripheral surface, a piston blade mounted in said slot and formed by a bundle of laminae having their side suria'ces'parallel to the impeller axis and each longitudinally movable independently of the others and a body of rubber-like material engaged and variably compressed by the inner ends of said laminae and exerting a resilient force on each lamina tending to hold the latter in engagement with the peripheral wall of the pump chamber.

3. In a pump of the type comprising a cylindrical pump chamber, a cylindrical impeller body smaller in diameter than said pump chamber and mounted to rotate in said chamber about an axis so displaced from the pump chamber axis that the peripheral walls of the body and chamber are in contact at one side of the pump chamber axis, said impeller body having a slot extending into it from its peripheral surface, a piston blade mounted in said slot and formed by a bundle of laminae oi self-lubricating metallic alloy material having their side surfaces parallel to the impeller axis and each longitudinally movable independently of the others and a body 0! rubber-like material engaged and variably compressed by the inner ends of said laminae and exerting a resilient force on each' lamina tending to hold the latter in engagement with the pe- 

